Capacity and Variability Analysis of the IEEE 802.11 MAC Protocol

View/Open

Date

Author

Metadata

Abstract

{\em Packet error} in the IEEE 802.11 network
%which is due to non-ideal channel condition and wireless device
variability,
is one source of performance degradation and its variability.
%Therefore the effect of packet errors, along with {\em collision
%avoidance} and {\em hidden terminals}, is among the most important
%considerations in performance anaylsis of the 802.11 MAC protocol.
Most of the previous works study how {\em collision avoidance} and
{\em hidden terminals} affect 802.11 performance metrics,
such as probability of a collision and saturation throughput.
In this paper we focus on the effect of packet errors on
capacity and variability of the 802.11 MAC protocol.
We develope a new analytical model, called $p_e$-Model, by extending
the existing model (Tay and Chua's model) to incorporate
{\em packet error probability} $p_e$.
With $p_e$-Model, we successfully analyze capacity and variability
of the 802.11 MAC protocol.
The variability analysis shows that increasing packet error probability by
$\Delta p_e$ has more effect on saturation throughput, than adding
$0.5 W \Delta p_e$ stations, where $W$ is the minimum contention window
size,
We also show the numerical validation of $p_e$-Model with 802.11
MAC-level simulator.
(UMIACS-TR-2003-45)